rick jameson did a wonderful article on this topic.he used a 22-250 all the wat up to the 375H&Hmag.

out of all the types he used the 375H&Hmag and the 22-250 shined. the 22-250 actually made it through to the target every time without deflecting.
i always used a NON lead tipped bullet when i hunt where shots could be up close in the brush. i don' t know if the round hits a twig with a lead nosed bullet compared to a NON lead nosed will help out.

i would go with whatever shoots best in your gun. but i would stay away from the BT' s due to those plastic tips snapping off when hitting a twig compared to a lead tipped that wuld deforma bit. but that is my opinion.

BTW.. how' s the kick and price of the ammo on the 270WSM?